Ice-embedded catalase crystals and amorphous carbon film were used as test specimens to demonstrate the feasibility and limitations of a 1024 x 1024 slow-scan CCD camera for imaging in a400 kV electron cryomicroscope. The structural resolution of the spot-scan images of ice-embedded catalase crystals was 8 _ and 4 _ at effective magnifications of 67,000x and 132,000x, respectively. These resolution limits are set by the finite pixel size of the slow-scan CCD camera. An amorphous carbon film was used to evaluate the damping effect of the specimen's Fourier spectrum by the modulation transfer function by comparing images of the same specimen area recorded on both the slow-scan CCD camera and photographic film. The ratio of the normalized diffraction amplitudes computed from these images becomes smaller at higher spatial frequency, showing that the Fourier amplitudes of CCD-recorded images fall off more rapidly, which is consistent with the expected modulation transfer function characteristics of the camera. Our analysis confirms the potential inaccuracies of the Fourier amplitudes in a certain range of spatial frequencies used for reconstruction if no correction is made on CCD captured images.